• Title/Summary/Keyword: Melting Method

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Preparation and Characterization of Piroxicam/Poloxamer Solid Dispersion Prepared by Melting Method and Solvent Method

  • Yu, Hang;Chun, Myung-Kwan;Choi, Hoo-Kyun
    • Journal of Pharmaceutical Investigation
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    • v.37 no.1
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    • pp.1-5
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    • 2007
  • Solid dispersions of piroxicam were prepared by melting method using poloxamer as a carrier. The results of DSC and XRD studies showed that the amorphous farm of piroxicam coexisted with the crystalline form in the solid dispersions. However, the ratio of crystalline form of piroxicam in the solid dispersion prepared by melting method decreased in comparison with the same ratio of the solid dispersion prepared by solvent method. As the ratio of poloxamer in the solid dispersion increased, the ratio of the amorphous form of piroxicam in the solid dispersion increased. The dissolution rate of piroxicam from the solid dispersions was significantly higher than that from piroxicam powder. In comparison to the solid dispersion prepared by solvent method, the dissolution rate of piroxicam from the solid dispersion prepared by melting method was higher. As the ratio of poloxamer in the solid dispersion prepared by melting method increased, the initial dissolution rate decreased, however, the total amount dissolved at the end of the study increased.

A Study on Fusion Welding Strength of PE pipe (PE배관의 융착 강도에 관한 연구)

  • Jun, Hung-Won;Kim, Yong-Soo;Tae, Soon-Ho
    • Journal of the Korean Society of Safety
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    • v.17 no.2
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    • pp.16-21
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    • 2002
  • At present the Polyethylene piping, on supporting LNG is widely used because of it's disposition which are anti-corrosion flexible and so on. However, it has a few kinds of risk which are the possibility of piping leak, the character of easily corroded and so on. For giving solution, this study is intended to experiment the intension of the PE pipe after melted and when it is melting, the condition which are temperature and pressure is changed. the melting condition in temperature and pressure is adapted identically. After melting, it's joint is tested as intension. The result is that the effect of temperature in intension is more effective than pressure. In $210^{\circ}C$, $20kg/cm^{2}$ condition, the melting intension has the highest. Compare to the Butt melting joint and the Saddle melting joint, the former was $214kg/cm^{2}$ and the latter was $50kg/cm^{2}(bead\;2{\sim}3mm)$ and $73kg/cm^{2}(bead\;5{\sim}7mm)$. It means that the Butt melting method has more intensive than saddle. Consequently, the result shows that the liability and safety when pipe melting method is used will improve in pipe installation.

A Study of Operation Performance Prediction Method for the Gasification Melting Furnace (가스화 용융로의 운전성능 예측기법에 관한 연구)

  • Lee, Min-Do;Choi, Sang-Min
    • 한국연소학회:학술대회논문집
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    • 2005.10a
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    • pp.43-49
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    • 2005
  • Social interest and request about low pollution waste treatment process are growing and gasification melting method, as a new technology concept, is risen. The necessity of engineering analysis to determine design standards and operation condition is required. In this study, the objective and function of components and operation process of various gasification melting furnaces such as shaft type, fluidized bed and Rotary Kiln type gasification melting furnace are reviewed and the design standard and operation range of gasification melting furnace are determined by inspecting the change of output and operation condition with input condition change.

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The finite difference analysis on temperature distribution by coordinate transformation during melting process of phase-change Material (상변화 물질의 용융과정에 있어서 좌표변환을 이용한 온도분포의 해석적 연구)

  • Kim, J.K.;Yim, J.S.
    • Solar Energy
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    • v.5 no.2
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    • pp.77-83
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    • 1985
  • An analysis is performed to investigate the influence of the buoyancy force and the thickness variation of melting layer in the containment that is filled with phase-change Material surrounding a cylindrical heating tube during melting process. The phase-change material is assumed to be initially solid at its phase-change temperature and the remaining solid at any given time is still at the phase-change temperature and neglecting the effect of heat transfer occuring within the solid. At the start of melting process, the thickness of melting layer is assumed to be a stefan-problem and after the starting process, the change of temperature and velocity is calculated using a two dimensional finite difference method. The governing equations for velocity and temperature are solved by a finite difference method which used SIMPLE (Semi Implicit Method Pressure linked Equations) algorithm. Results are presented for a wide range of Granshof number and in accordance with the time increment and it is founded that two dimensional fluid flow occurred by natural convection decreases the velocity of melting process at the bottom of container. The larger the radius of heating tube, the higher heat transfer is occurred in the melting layer.

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Measurement of Cement Content on Concrete Using the Method of Hydrochloric Acid Melting Heat (염산용해열법을 이용한 콘크리트의 단위시멘트량 추정)

  • Kim, Sang-Min;Sin, Se-Jun;Hyun, Seung Yong;Kim, Jong;Han, Min-Cheol;Han, Cheon-Goo
    • Proceedings of the Korean Institute of Building Construction Conference
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    • 2020.11a
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    • pp.102-103
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    • 2020
  • In this study, the effect of the change in the cement contents on the basic properties of the concrete and the estimation of the cement contents of hardened concretes using the hydrochloric acid melting heat. As a result of the study, as the cement contents increased, the fluidity and compressive strength increased, and there was no significant difference in the air contents and the unit volume mass. In addition, it showed a high correlation when compared with the estimated cement contents derived using the hydrochloric acid melting and the cement contents at the time of mixing. Therefore, it is considered that the hydrochloric acid melting is possible as a method of estimating the cement contents of concrete.

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Algorithm for Segmenting Resin Bleed and Melting on the Surface of QFN Packages (QFN 패키지의 Resin Bleed와 Melting 검출 알고리즘)

  • Wang, Ming-Jie;Park, Duck-Chun;Joo, Hyo-Nam;Kim, Joon-Seek
    • Journal of Institute of Control, Robotics and Systems
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    • v.15 no.9
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    • pp.899-905
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    • 2009
  • There are many different types of surface defects on semiconductor Integrated Chips (IC's) caused by various factors during manufacturing process, such as Scratch, Flash, Resin bleed, and Melting. These defects must be detected and classified by an inspection system for productivity improvement and effective process control. Among defects, in particular, Resin bleed and Melting are the most difficult ones to classify accurately. The brightness value and the shape of Resin bleed and Melting defects are so similar that normally it is difficult to classify the Resin bleed and Melting. In this paper, we propose a segmenting method and a set of features for detecting and classifying the Resin bleed and Melting defects.

A Study on the Optimum Chemical Composition of Insert Metal for Liquid Phase Diffuse Bonding (액상확산접합용 인서트금속의 화학조성 최적화에 관한 연구)

  • 김대업;정승부;강정윤
    • Journal of Welding and Joining
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    • v.18 no.5
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    • pp.90-97
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    • 2000
  • Effect of alloy elements on joinability of insert metal for liquid phase diffusion bonding of heat resistant alloys was investigated in this study. Also, optimum chemical composition of insert metal was explained using interpolation method. The insert metals utilized was commercial Ni-base amorphous foils and newly developed Ni-base filler metals with B, Si and Cr in this study. Melting point and critical interlayer width(CIW) decreased with increasing additional amount of B, Si and Cr, melting point lowering element of the insert metal. Optimized chemical composition of insert metals could be estimated by interpolation method. The optimum amount of B, Si, Cr addition into the insert metal were found to be about 3%, 4% and 3%, respectively. The measured characteristic values, melting point, microhardness in the bonded interlayer and CIW of the insert metals were the almost identical to ones of the calculated results by interpolation method.

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High Temperature Vaporization of the High Melting Point Oxides (고융점 산화물에 대한 고온 증발)

  • 이홍림
    • Journal of the Korean Ceramic Society
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    • v.15 no.2
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    • pp.72-78
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    • 1978
  • The vapor pressure of the high melting point oxides, MgO, $Cr_2O_3$, and $MgCr_2O_4$ were measured over the temperature range 1300 to 175$0^{\circ}C$ under vacuum <$10^{-5}$ torr by the Langmuir and the Knudsen method. The Langmuir vapor pressure was increased with elevating temperature and with increasing porosity of the specimen. The difference between the vapor preseures measured by the Langmuir and the Knudsen method was decreased with elevating temperature and the Langmuir vapor pressure finally reached the Knudsen vapor pressure at the melting point when extrapolated. The vapor pressure of other important oxides with high melting points, i.e., $Al_2O_3$, $ThO_2$, $Yb_2O_3$ and $Y_2O_3$ were cited from the references. The Langmuir and the Knudsen vapor pressure of these oxides also showed the same results, i.e., they showed the same value at their melting points.

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The evaluation of the compatibility of recycling melting slag from incinerator ashes as construction materials (소각재 용융슬래그의 건설재료로서 재활용시 적합성 평가)

  • 한영수;이재영
    • Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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    • 2001.04a
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    • pp.30-33
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    • 2001
  • Melting is one of the most effective treatments for stabilizing heavy metals and also creates high value by-products. In this study, authors evaluated the leaching characteristics of heavy metals in melting slag obtained from incinerator ashes. In order to evaluate the environmental compatibility of the recycled melting slag, the samples analysed various leaching tests of heavy metals were raw incinerator ashes, melting slag and the construction materials recycled from melting slag. As the results: (1) The leaching concentrations of tile melting slag were lower than those of the raw incinerator ashes in the experiment performed in accordance with Korea Standard Leaching Test (KSLT). (2) The result of leaching test with the method of RG Min-StB 93. FGSV Forschungsgesellschaft fur Stra $\beta$ en- und Verkehrswesen) met the requirements in German. (3) The compressive strengths of mortar samples used for evaluating the feasibility of recycling the melting slag as construction materials also showed the suitable range for recycling (4) Melting slag was considered the stable materials with respect to the chemical stability against chemical solutions with various pH conditions.

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Zone-melting of EPD $YBa_2Cu_3O_x$ Thick Film under Low Oxygen Partial Pressure

  • Soh, Dea-Wha;Fan, Zhanguo
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2003.11a
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    • pp.263-266
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    • 2003
  • The fine $YBa_2Cu_3O_x$ powder ($0.2{\sim}1.0\;{\mu}m$) is produced by sol-gel method, and electrophoresis deposition is used for the preparation of $YBa_2Cu_3O_x$ thick films which are deposited on Ag wire. The oriented $YBa_2Cu_3O_x$ was tried to be prepared by the zone-melting method under low oxygen partial pressure. The orientation and the phase composition were examined by the X-ray diffraction and the superconductivities were measured by 4 line method. The critical current densities are still quite low, which may be due to unsuitable technical parameters for zone-melting of $YBa_2Cu_3O_x$ thick films. Therefore the heat treatment condition and controlling of low oxygen partial pressure should be improved in the future experiment.

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